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Allowance for naturally occurring ester

The need to allow an amendment of the prescribed test method for ester content (EN 14103) to account for the presence of naturally occurring C-17 methyl ester, which is used as an internal standard, has been acknowledged internationally, and has — for example — been provided for in the the Australian Biodiesel Standard Amendment 2009.

The alternative method is in line with the modification proposed in the scientific paper "Ester content evaluation in biodiesel from animal fats and lauric oils" by international specialists in this area. The Australian amendment is based on this paper as well.

The ester C content, expressed as a mass fraction in percent, is calculated using the following formula:

Where: ΣA is the total peak area from the methyl ester in C14 to that in C24:1 in 8.2;AE is the peak area corresponding to methyl heptadecanoate in 8.1;AEI is the peak area corresponding to methyl heptadecanoate in 8.2; CEI is the concentration, in milligrams per millilitre, of the methyl heptadecanoate solution (5.3) being used; VEI is the volume, in millilitres, of the methyl heptadecanoate solution (5.3) being used;m1 is the mass, in milligrams, of the sample in 8.1;m2 is the mass, in milligrams, of the sample in 8.2.

10.2 Determination of linolenic acid methyl ester

The linolenic acid methyl ester content L, expressed as a mass fraction in percent, is calculated using the following formula:

Where: ΣA is the total peak area from the methyl ester in C14 to that in C24:1 in 8.2;AE is the peak area corresponding to methyl heptadecanoate in8.1; AEI is the peak area corresponding to methyl heptadecanoate in 8.2; AL is the peak area corresponding to linolenic acid methyl ester in 8.2;m1 is the mass, in milligrams, of the sample in 8.1;m2 is the mass, in milligrams, of the sample in 8.2.